There is increasing interest in improving the safety of automobiles using on-board safety systems. One approach in the prior art is the use of radar based collision avoidance systems. For example, a radar based collision avoidance system can provide information on the distance between cars even when there is poor visibility. However, radar based automotive systems can be expensive, with some radar systems costing several thousand dollars.
Image sensors, such as Complementary Metal Oxide Semiconductor (CMOS) image sensors, detect light in the visible and/or infrared wavelengths. Consequently image sensors can also be utilized to improve automobile safety. Conventionally, image sensors have been widely used as in the context of rear-view automobile cameras to assist drivers to safely park their cars. Such rear-view automobile camera applications are inherently designed for low-speed, short distance collision avoidance. In such rear-view camera applications the resolution of the camera and the frame rate can be comparatively low.
Forward-looking camera systems are also of interest to improve automobile safety. Forward looking automobile camera systems, such as that proposed in Pat. Pub. US 2007/0242153, typically include an image recognition process to automatically identify objects within an image and adjust the image sensor parameters across the entire image based on analyzing a region of interest and then readjusting a sensor setting (e.g., gain for the entire image). However, there is substantial vibration and shock in automobiles, which makes it difficult to integrate a zoom lens with a forward looking camera system in a cost effective manner. Consequently, in conventional forward looking automobile camera systems the resolution may be too poor to effectively support many desirable applications. Additionally, prior art forward looking automobile camera systems, such as that disclosed in US 2007/0242153 typically provide only a very limited capability to control a limited subset of sensor parameters (e.g., gain) for the entire image based on analysis of a single region of interest. As a consequence of the combination of these limitations, conventional forward looking automobile camera systems can not be used in a cost-effective manner to support the suite of safety applications that automobile designers desire.
Therefore, what is desired is an improved forward looking image sensing system and method applicable to support automobile safety applications.